package com.game.core.db.service.jedis;

import java.nio.ByteBuffer;
import static com.game.core.db.service.jedis.Protocol.Keyword.COUNT;
import static com.game.core.db.service.jedis.Protocol.Keyword.MATCH;
import com.game.core.db.service.jedis.Protocol.Keyword;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.EnumMap;
import java.util.List;
import java.util.Map;

import com.game.core.db.service.jedis.util.SafeEncoder;

public class ScanParams {

	private final Map<Keyword, ByteBuffer> params = new EnumMap<Keyword, ByteBuffer>(Keyword.class);

	public final static String SCAN_POINTER_START = String.valueOf(0);
	public final static byte[] SCAN_POINTER_START_BINARY = SafeEncoder.encode(SCAN_POINTER_START);

	public ScanParams match(final byte[] pattern) {
		params.put(MATCH, ByteBuffer.wrap(pattern));
		return this;
	}

	/**
	 * @see <a href="https://redis.io/commands/scan#the-match-option">MATCH option
	 *      in Redis documentation</a>
	 */
	public ScanParams match(final String pattern) {
		params.put(MATCH, ByteBuffer.wrap(SafeEncoder.encode(pattern)));
		return this;
	}

	/**
	 * @see <a href="https://redis.io/commands/scan#the-count-option">COUNT option
	 *      in Redis documentation</a>
	 */
	public ScanParams count(final Integer count) {
		params.put(COUNT, ByteBuffer.wrap(Protocol.toByteArray(count)));
		return this;
	}

	public Collection<byte[]> getParams() {
		List<byte[]> paramsList = new ArrayList<byte[]>(params.size());
		for (Map.Entry<Keyword, ByteBuffer> param : params.entrySet()) {
			paramsList.add(param.getKey().raw);
			paramsList.add(param.getValue().array());
		}
		return Collections.unmodifiableCollection(paramsList);
	}

	String match() {
		if (params.containsKey(MATCH)) {
			return new String(params.get(MATCH).array());
		} else {
			return null;
		}
	}

	Integer count() {
		if (params.containsKey(COUNT)) {
			return params.get(COUNT).getInt();
		} else {
			return null;
		}
	}
}
